/*
** ZABBIX
** Copyright (C) 2000-2005 SIA Zabbix
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**/

#include "common.h"
#include "sysinfo.h"
#include "md5.h"
#include "file.h"

int	VFS_FILE_SIZE(const char *cmd, const char *param, unsigned flags, AGENT_RESULT *result)
{
	struct stat	buf;
	char		filename[MAX_STRING_LEN];

	assert(result);

	init_result(result);

	if (num_param(param) > 1)
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 1, filename, sizeof(filename)))
		return SYSINFO_RET_FAIL;

	if (0 != zbx_stat(filename, &buf))
		return SYSINFO_RET_FAIL;

	SET_UI64_RESULT(result, buf.st_size);

	return SYSINFO_RET_OK;
}

int	VFS_FILE_TIME(const char *cmd, const char *param, unsigned flags, AGENT_RESULT *result)
{
	struct stat	buf;
	char		filename[MAX_STRING_LEN], type[8];

	assert(result);

	init_result(result);

	if (num_param(param) > 2)
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 1, filename, sizeof(filename)))
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 2, type, sizeof(type)))
		*type = '\0';

	if (0 != zbx_stat(filename, &buf))
		return SYSINFO_RET_FAIL;

	if ('\0' == *type || 0 == strcmp(type, "modify"))	/* default parameter */
	{
		SET_UI64_RESULT(result, buf.st_mtime);
	}
	else if (0 == strcmp(type, "access"))
	{
		SET_UI64_RESULT(result, buf.st_atime);
	}
	else if (0 == strcmp(type, "change"))
	{
		SET_UI64_RESULT(result, buf.st_ctime);
	}
	else
		return SYSINFO_RET_FAIL;

	return SYSINFO_RET_OK;
}

int	VFS_FILE_EXISTS(const char *cmd, const char *param, unsigned flags, AGENT_RESULT *result)
{
	struct stat	buf;
	char		filename[MAX_STRING_LEN];

	assert(result);

	init_result(result);

	if (num_param(param) > 1)
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 1, filename, sizeof(filename)))
		return SYSINFO_RET_FAIL;

	SET_UI64_RESULT(result, 0);

	if (0 == zbx_stat(filename, &buf))	/* File exists */
		if (S_ISREG(buf.st_mode))	/* Regular file */
			SET_UI64_RESULT(result, 1);

	return SYSINFO_RET_OK;
}

int	VFS_FILE_REGEXP(const char *cmd, const char *param, unsigned flags, AGENT_RESULT *result)
{
	char	filename[MAX_STRING_LEN], regexp[MAX_STRING_LEN], encoding[32];
	char	buf[MAX_BUF_LEN], *utf8;
	int	f, nbytes, len;

	assert(result);

	init_result(result);

	if (num_param(param) > 3)
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 1, filename, sizeof(filename)))
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 2, regexp, sizeof(regexp)))
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 3, encoding, sizeof(encoding)))
		*encoding = '\0';

	zbx_strupper(encoding);

	if (-1 == (f = zbx_open(filename, O_RDONLY)))
		return SYSINFO_RET_FAIL;

	while (0 < (nbytes = zbx_read(f, buf, sizeof(buf), encoding)))
	{
		utf8 = convert_to_utf8(buf, nbytes, encoding);
		if (NULL != zbx_regexp_match(utf8, regexp, &len))
		{
			zbx_rtrim(utf8, "\r\n ");
			SET_STR_RESULT(result, utf8);
			break;
		}
		zbx_free(utf8);
	}

 	close(f);

	if (-1 == nbytes)	/* error occurred */
		return SYSINFO_RET_FAIL;

	if (0 == nbytes)	/* EOF */
		SET_STR_RESULT(result, strdup("EOF"));

	return SYSINFO_RET_OK;
}

int	VFS_FILE_REGMATCH(const char *cmd, const char *param, unsigned flags, AGENT_RESULT *result)
{
	char	filename[MAX_STRING_LEN], regexp[MAX_STRING_LEN], encoding[32];
	char	buf[MAX_BUF_LEN], *utf8;
	int	f, nbytes, len, res;

	assert(result);

	init_result(result);

	if (num_param(param) > 3)
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 1, filename, sizeof(filename)))
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 2, regexp, sizeof(regexp)))
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 3, encoding, sizeof(encoding)))
		*encoding = '\0';

	zbx_strupper(encoding);

	if (-1 == (f = zbx_open(filename, O_RDONLY)))
		return SYSINFO_RET_FAIL;

	res = 0;

	while (0 == res && 0 < (nbytes = zbx_read(f, buf, sizeof(buf), encoding)))
	{
		utf8 = convert_to_utf8(buf, nbytes, encoding);
		if (NULL != zbx_regexp_match(utf8, regexp, &len))
			res = 1;
		zbx_free(utf8);
	}

 	close(f);

	if (-1 == nbytes)	/* error occurred */
		return SYSINFO_RET_FAIL;

	SET_UI64_RESULT(result, res);

	return SYSINFO_RET_OK;
}

/* MD5 sum calculation */
int	VFS_FILE_MD5SUM(const char *cmd, const char *param, unsigned flags, AGENT_RESULT *result)
{
	char		filename[MAX_STRING_LEN];
	int		f, i, nbytes;
	struct stat	buf_stat;
	md5_state_t	state;
	u_char		buf[16 * 1024];
	char		*hashText = NULL;
	size_t		sz;
	md5_byte_t	hash[MD5_DIGEST_SIZE];

	assert(result);

	init_result(result);

	if (num_param(param) > 1)
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 1, filename, sizeof(filename)))
		return SYSINFO_RET_FAIL;

	if (0 != zbx_stat(filename, &buf_stat))
		return SYSINFO_RET_FAIL;	/* Cannot stat() file */

	if (buf_stat.st_size > 64 * 1024 * 1024)
		return SYSINFO_RET_FAIL;	/* Will not calculate MD5 for files larger than 64M */

	if (-1 == (f = zbx_open(filename, O_RDONLY)))
		return SYSINFO_RET_FAIL;

	md5_init(&state);

	while ((nbytes = (int)read(f, buf, sizeof(buf))) > 0)
	{
		md5_append(&state, (const md5_byte_t *)buf, nbytes);
	}

	md5_finish(&state, hash);

	close(f);

	if (nbytes < 0)
		return SYSINFO_RET_FAIL;

	/* Convert MD5 hash to text form */
	sz = MD5_DIGEST_SIZE * 2 + 1;
	hashText = zbx_malloc(hashText, sz);

	for (i = 0; i < MD5_DIGEST_SIZE; i++)
	{
		zbx_snprintf(&hashText[i << 1], sz - (i << 1), "%02x", hash[i]);
	}

	SET_STR_RESULT(result, hashText);

	return SYSINFO_RET_OK;
}

/*
 * Code for cksum is based on code from cksum.c
 */
static u_long crctab[] = {
	0x0,
	0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
	0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
	0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
	0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
	0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
	0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
	0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
	0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
	0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
	0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
	0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
	0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
	0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
	0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
	0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
	0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
	0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
	0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
	0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
	0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
	0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
	0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
	0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
	0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
	0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
	0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
	0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
	0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
	0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
	0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
	0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
	0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
	0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
	0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
	0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
	0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
	0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
	0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
	0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
	0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
	0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
	0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
	0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
	0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
	0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
	0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
	0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
};

/*
 * Compute a POSIX 1003.2 checksum.  These routines have been broken out so
 * that other programs can use them.  The first routine, crc(), takes a file
 * descriptor to read from and locations to store the crc and the number of
 * bytes read.  The second routine, crc_buf(), takes a buffer and a length,
 * and a location to store the crc.  Both routines return 0 on success and 1
 * on failure.  Errno is set on failure.
 */
int	VFS_FILE_CKSUM(const char *cmd, const char *param, unsigned flags, AGENT_RESULT *result)
{
	char			filename[MAX_STRING_LEN];
	register int		i, nr;
	/* AV Crashed under 64 platforms. Must be 32 bit!
	 * register u_long crc, len; */
	register uint32_t	crc, len;
	u_char			buf[16 * 1024];
	u_long			cval;
	int			f;

	assert(result);

	init_result(result);

	if (num_param(param) > 1)
		return SYSINFO_RET_FAIL;

	if (0 != get_param(param, 1, filename, sizeof(filename)))
		return SYSINFO_RET_FAIL;

	if (-1 == (f = zbx_open(filename, O_RDONLY)))
		return SYSINFO_RET_FAIL;

	crc = len = 0;

	while ((nr = (int)read(f, buf, sizeof(buf))) > 0)
	{
		len += nr;
		for (i = 0; i < nr; i++)
			crc = (crc << 8) ^ crctab[((crc >> 24) ^ buf[i]) & 0xff];
	}

	close(f);

	if (nr < 0)
		return SYSINFO_RET_FAIL;

	/* Include the length of the file. */
	for (; len != 0; len >>= 8)
		crc = (crc << 8) ^ crctab[((crc >> 24) ^ len) & 0xff];

	cval = ~crc;

	SET_UI64_RESULT(result, cval);

	return SYSINFO_RET_OK;
}
